package dao.impl;

import dao.UserDao;
import pojo.User;
import service.UserService;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class UserDaoImpl implements UserDao {
    @Override
    public List<User> findAll() {
        List<User> list=new ArrayList<>();

        Connection connection =null;
        PreparedStatement preparedStatement =null;
        ResultSet resultSet =null;
        //1、 加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2、获取连接
            connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8", "root", "coup");
//            if (connection!=null){
//                System.out.println("连接成功");
//            }
            //3.sql
            String sql="select * from user";
            //4.预编译sql
            preparedStatement = connection.prepareStatement(sql);
            //5.执行sql
            resultSet = preparedStatement.executeQuery();
            //6.遍历结果
            while(resultSet.next()){
                User user=new User();
                user.setId(resultSet.getInt("id"));
                user.setName(resultSet.getString("name"));
                user.setPass(resultSet.getString("pass"));
                list.add(user);
            }
            return list;
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        finally{
            //7.关闭资源:从后往前依次关闭
            try {
                if(resultSet!=null){
                    resultSet.close();
                }
                if(preparedStatement!=null){
                    preparedStatement.close();
                }
                if(connection!=null){
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }


    }
}
